Spin-rinse-dryer

ABSTRACT

An inventive vertical spin-dryer is provided. The inventive spin-dryer may have a shield system positioned to receive fluid displaced from a substrate vertically positioned within the spin-dryer. The shield system may have one or more shields positioned to at least partially reflect fluid therefrom as the fluid impacts the shield. The one or more shields are angled to encourage the flow of fluid therealong, and are preferably hydrophilic to prevent droplets from forming. Preferably the shield system has three shields positioned in a horizontally and vertically staggered manner so that fluid is transferred from a substrate facing surface of a first shield to the top or non-substrate-facing surface of an adjacent shield, etc. A pressure gradient may be applied across the interior of the spin-dryer to create an air flow which encourages fluid to travel along the shield system in a desired direction. A sensor adapted to facilitate desired flywheel position, an openable gripper having a remote actuator, a radiused gripper and a source of inert drying gas are also provided in individual embodiments.

[0001] This application is a division of U.S. patent application Ser. No. 09/544,660, filed Apr. 6, 2000, which claims priority from U.S. provisional application Serial No. 60/128,257, filed Apr. 8, 1999, both of which are hereby incorporated by reference herein in their entirety.

FIELD OF THE INVENTION

[0002] The present invention relates to the cleaning and drying of thin disks such as glass substrates, flat panel displays, patterned or unpatterned semiconductor substrates and the like. More specifically, the present invention relates to an improved spin-rinse-dryer for rinsing and drying semiconductor substrates.

BACKGROUND OF THE INVENTION

[0003] As semiconductor device geometries continue to decrease, the importance of ultra clean processing increases. Aqueous cleaning within a tank of fluid (or a bath) followed by a rinsing process (e.g., by submersing the substrate in rinsing fluid, or by spraying the substrate with rinsing fluid) achieves desirable cleanliness levels. However, after rinsing is complete, absent use of a drying apparatus, the rinsing fluid would evaporate from the substrate's surface causing streaking, spotting and/or leaving bath residue on the surface of the substrate. Such streaking, spotting and residue can cause subsequent device failure. Accordingly, much attention has been directed to improved methods for drying a substrate after a final rinsing step.

[0004] In addition to providing streak-free drying, such methods should be capable of quickly drying the substrate so as to increase throughput, and should not present a bottleneck for the overall substrate processing system.

[0005] Accordingly, a need exists for a method and apparatus that quickly and reliably rinses and dries a substrate such as a semiconductor substrate.

SUMMARY OF THE INVENTION

[0006] The present invention provides an improved spin-rinse-drier (SRD) comprising a substrate support for holding and rotating a vertically oriented substrate; a source of fluid adapted to supply fluid preferably to both surfaces of a substrate positioned on the substrate support; and, in a first aspect, at least a first shield designed to remove rinsing fluid from the vicinity of the substrate, and particularly to remove rinsing fluid from areas which may allow droplets to fall onto a substrate positioned therebelow. Accordingly, in the first aspect the shield is positioned to receive fluid displaced from a substrate rotating on the substrate support, and is adapted to reflect the received fluid away from the substrate. In a second aspect, a shield is positioned to receive fluid displaced from a substrate rotating on the substrate support, and comprises a hydrophilic substrate facing surface. The entire substrate facing surface of the shield may be hydrophilic, or a hydrophilic wafer facing surface may be mounted (e.g., in the region above the substrate) to a non-hydrophilic shield. In a third aspect, the inventive SRD comprises a shield system having a plurality of vertically and horizontally staggered shields positioned to receive fluid displaced from a substrate rotating on the substrate support, and adapted to carry fluid away from the area above the substrate. As used herein, a shield or shield system described as vertically staggered, or as having various elevations and slopes, refers to the upper region of the shield. It will be understood that the sides and lower regions of the shield may have other shapes.

[0007] Further aspects of the invention comprise various combinations of the aspects described above, and/or may comprise further advantageous features. For example, the inventive SRD may have a pressure gradient applied to induce laminar airflow across the surface of the substrate to enhance drying. The plurality of shields can be positioned to further direct the airflow toward the substrate, and may have close vertical spacing such that the airflow enhances the movement of fluid along the shields in a desired direction. The lid of the inventive SRD may be hydrophilic (to enhance fluid sheeting rather than droplet formation) and/or may be sloped to encourage fluid flow in a desired direction. Yet further aspects comprise a sensor and flag adapted to sense a desired position of the flywheel, comprise applying rinsing fluid to the substrate while rotating the substrate at a speed of at least 400 revolutions per minute, comprise a plurality of openable grippers that are biased to a closed position, and have remote pins adapted to selectively open the grippers, grippers that have a hole or slot located at a point of contact between the gripper and a substrate and/or comprise radiused grippers preferably radiused in a plurality of directions.

[0008] Other features and advantages of the present invention will become more fully apparent from the following detailed description of the preferred embodiments, the appended claims and the accompanying drawings.

BRIEF DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009]FIGS. 1A and 1B are a perspective view of the frontside and the backside, respectively, of an inventive SRD;

[0010]FIG. 2 is a side cross-sectional view of the inventive SRD of FIG. 1;

[0011]FIG. 3 is a side cross-sectional view of the shield system of the inventive SRD of FIG. 1;

[0012]FIG. 4 is a front cross-sectional view of the inventive SRD of FIG. 1;

[0013]FIGS. 5A and 5B are a side view and a front view, respectively, of the gripper end effectors of the inventive SRD of FIG. 1;

[0014]FIG. 5C is a perspective view of the end effector 407;

[0015]FIGS. 6A and 6B are side views of the grippers of FIGS. 5A-C, respectively showing the grippers in an open and a closed position; and

[0016]FIGS. 7A and 7B are a side and a front cross sectional view, respectively, showing an optional drying mechanism employed within the inventive SRD of FIG. 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] For convenience, throughout the drawings, the left-most digit of a reference number identifies the drawing in which the reference number first appears.

[0018]FIGS. 1A and 1B are a front and back perspective view, respectively, of an inventive SRD 101 for rinsing, spinning and drying a vertically oriented thin disk such as a semiconductor substrate. The SRD 101 comprises a housing 103; a front side 103 a of the housing 103 has a plurality of openings or vents 105 a-f that allow clean air to enter the housing 103. A plenum 107 is positioned along a backside 103 b of the housing 103. The plenum 107 is exhausted via an exhaust line 109, which is coupled to a pump (not shown). A top 103 c of the housing 103 is bolted to the side walls of the housing 103 so that the top 103 c may be removed therefrom should the SRD 101's internal components need servicing. The top 103 c of the SRD housing 103 slopes from a first side wall 103 d to a second side wall 103 e so that any fluid which collects on the top 103 c will flow to the lower side thereof, and down the second sidewall 103 e. A heat lamp assembly 111 comprises a housing 113 mounted to the front side 103 a of the SRD housing 103, a heat lamp 115 contained within the housing 113, and a quartz shield 117. The quartz shield 117 comprises a portion of the front side 103 a of the SRD housing 103 which is made of quartz so as to allow the transmission of light from the heat lamp 115 to a substrate 201 (see FIG. 2). The heat lamp assembly 111 extends the length of the substrate 201's diameter such that the entire substrate 201 is heated thereby as the substrate 201 rotates.

[0019] The top 103 c of the SRD housing 103 has an opening 118 sized to allow substrate insertion and extraction. A slideable door 120 is mounted on a pair of tracks 123 a, 123 b so as to slide back and forth to open and close the opening 111. A bottom wall 103 f of the SRD housing slopes to a low point 117. A drain 119 is coupled to the bottom wall 103 f at the low point 117 to remove rinsing fluid therefrom. A pair of legs 121 a, 121 b coupled to the SRD housing's bottom wall 103 f support the SRD 101. The internal components of the inventive SRD 101 are described with reference to FIG. 2.

[0020]FIG. 2 is a side cross-sectional view showing pertinent parts of the inventive SRD 101 of FIG. 1. Within the inventive SRD 101 a substrate 201 is shown supported by a pair of grippers G which extend from a rotateable flywheel 205. Additional grippers (referenced as 403 a-c and 405 a-b) can be seen with reference to FIG. 4. The flywheel 205 is coupled to a motor 207 via an opening in the backside 103 b of the SRD housing. A pair of rinsing fluid nozzles 208 a, 208 b are coupled to a source of rinsing fluid (not shown), and are positioned to supply rinsing fluid to the center of the front and back surfaces of the substrate 201, respectfully. A proximity sensor 209 (e.g., a capacitive or inductive based proximity sensor) protrudes through the backside 103 b of the SRD housing so as to detect the presence of a metal flag 211 mounted to the flywheel 205. A shield system comprising a main shield 213, a lower shield 215, and a higher shield 217 surrounds the substrate 201 and is shown separately in FIG. 3 and described further with reference thereto.

[0021]FIG. 3 is a side cross-sectional view of the shield system of the inventive SRD of FIG. 1. The preferred main shield 213 can be described as a slice of a cone which surrounds the entire perimeter of the substrate 201 positioned on the flywheel 205 (FIG. 2). Thus, the main shield 213 slants from a larger diameter to a smaller diameter which is closest to the flywheel 205 (FIG. 2). These diameters preferably are selected such that the substrate facing surface of the main shield 213 has an angle in the range of 5° to 45°, (from normal) and most preferably 18°. The substrate facing surface of the main shield 213 preferably is smooth and hydrophilic, such that fluid displaced from the substrate 201 which strikes the substrate facing surface of the main shield 213 reflects therefrom and/or flows therealong preventing droplets from forming and dripping on the substrate 201. Because hydrophilic materials (e.g., quartz) are expensive a non-hydrophilic shield (e.g., a plastic shield) maybe employed, and a hydrophilic material such as quartz mounted inside a desired portion of the non-hydrophilic shield so as to form a hydrophilic wafer facing surface or liner. For example, a quartz liner 213 a may be employed in the region above the substrate (e.g., in the upper half of the main shield 213), as shown in FIG. 3. The substrate facing surface and the outer surface of the main shield 213 are parallel in the preferred embodiment such that the outer surface and the substrate facing surface share a common slope. The outer surface of the main shield 213 preferably has a raised region 301 a, 301 b along both edges to prevent rinsing fluid from running over the respective edge of the main shield 213's top outer surface and onto the substrate 201 positioned therebelow.

[0022] Because the main shield 213 surrounds the substrate 201, the main shield 213 is coupled to the first sidewall 103 d (FIG. 1) and to the second sidewall 103 e (FIG. 2) of the SRD housing via a pair of pneumatically driven links 401 a, 401 b (FIG. 4). Thus the main shield 213 moves away from the grippers G (FIG. 2) to enable substrate 201 insertion and extraction. The main shield 213 may move uniformly forward away from the grippers G, or the top region of the main shield 213 may tilt forward sufficiently to enable insertion and extraction of the substrate 201.

[0023] Referring again to FIG. 3, the preferred lower shield 215 also may be described as a cone-shaped slice, which surrounds the upper half of the substrate 201's perimeter. The lower shield 215 slants from a larger radius to a smaller radius which is closest to the flywheel 205 (FIG. 2). These radii are selected such that the substrate facing surface of the lower shield 215 has an angle in the range of 5 to 45°, and most preferably 36°, so that rinsing fluid flows therealong away from the substrate 201. The substrate facing surface and the outer surface of the lower shield 215 also are parallel in the preferred embodiment. The lower shield 215 is coupled to the backside 103 b of the SRD housing via a bracket 303.

[0024] Like the main shield 213 and the lower shield 215, the higher shield 217 may be described as a cone-shaped slice, which surrounds the upper quarter of the substrate 201's perimeter. The higher shield 217 slants from a larger radius to a smaller radius which is closest to the flywheel 205 (FIG. 2). These radii are selected such that the substrate facing surface of the higher shield 217 has an angle in the range of 5 to 45°, and most preferably 10°, so that rinsing fluid flows therealong toward the main shield 213 (as further described below). The higher shield 217 is coupled to the front side 103 a (FIG. 1) of the SRD housing via a bracket 305.

[0025] The main shield 213, the lower shield 215-and the higher shield 217 are arranged in a vertically and horizontally staggered manner to receive fluid displaced from the flywheel 205 (FIG. 2) as the flywheel 205 rotates, and are adapted to carry fluid away from the region above the substrate 201. In the preferred embodiment, the lower elevation (or smaller diameter) edge of the higher shield 217 overlaps the higher elevation (or larger diameter) edge of the main shield 213, and the lower elevation edge of the main shield 213 overlaps the higher elevation edge of the lower shield 215, as shown. The edges of the adjacent shields are closely spaced vertically (e.g., 0.3 inches) so that in the regions above the substrate 201, fluid flows from the substrate facing surface of the higher elevation shield to the outer surface of the nearest lower elevation shield with minimal splashing. The close vertical spacing of the shields 213, 215 and 217 also facilitates transfer of fluid along the shield system (as further described below with respect to the overall operation of the inventive SRD 101). Although the preferred higher and lower shields extend around only the top portion of the substrate, either or both can extend to surround any portion of, or the entire perimeter of the substrate. Such extension will facilitate air flow around the entire perimeter of the substrate, and prevent turbulence. Similarly, the main shield 213 can provide desired fluid flow and fluid reflection when extending along only the upper portion of the substrate 201.

[0026]FIG. 4 is a front cross-sectional view of the inventive SRD of FIG. 1. A plurality of grippers (“G”of FIG. 2) which support the substrate 201 comprise three fixed grippers 403 a-c and two moveable grippers 405 a-b. The fixed grippers 403 a-c and the moveable grippers 405 a-b are coupled to the flywheel 205. Each of the grippers 403 a-c, 405 a-b comprises an end effector 407 and a finger portion 409. The finger portions 409 are configured for either stationary or moveable coupling to the flywheel 205, as described with reference to FIGS. 6A and 6B. The end effector 407 of both the fixed grippers 403 a-c and the moveable grippers 405 are configured so as to support the substrate 201 with minimal contact and so as to avoid trapping fluid against the substrate 201. The configuration of the end effector 407 is best understood with reference to FIGS. 5A and 5B.

[0027]FIGS. 5A and 5B are a side view and a front view, respectively, of the end effector 407 of the inventive SRD 101. FIG. 5C is a perspective view of the end effector 407. The end effector 407 is comprised of two tip regions 411 a, 411 b, which join forming a valley, adapted to support the substrate 201 with minimal contact. A slot or hole 413 may be located in the region where the tip regions 411 a, 411 b join, such that fluid may flow through the hole 413, away from the substrate 201.

[0028] The fixed grippers 403 a-c are spaced along the bottom of the flywheel 205 so as to support the substrate 201 in a fixed position both horizontally and vertically, when a substrate is lowered thereto. The tip regions 411 a, 411 b are radiused both in the longitudinal direction (between the finger portion 409 and the substrate 201) and in the lateral direction (into and out of the page with reference to FIG. 5A), as shown in FIGS. 5A and 5B, respectively. The surfaces of the tip regions 411 a, 411 b are smooth, and preferably hydrophilic. Thus as the flywheel 205 rotates, fluid flows along the smooth radial surfaces of the tip regions 411 a, 411 b and does not remain in contact with the substrate 201. Ideally, the plurality of grippers 403 a-c, 405 a-b are positioned such that the center of the substrate 201 supported thereby is below the center of the flywheel 205 (e.g., 0.1-3 mm below and most preferably 1 mm below the flywheel's center) in the direction of the fixed grippers 403 a-c. In this manner, as the substrate 201 rotates the substrate 201 is forced toward the fixed grippers 403 a-c. Because the fixed grippers 403 a-c do not open, the substrate 201 is unlikely to become unseated as the flywheel 205 rotates.

[0029]FIGS. 6A and 6B are side perspective views of the moveable grippers 405 a, 405 b in an open position and in a closed position, respectively. Each of the moveable grippers 405 a, 405 b, respectively, comprises a base portion 601 a, 601 b. To open the moveable grippers 405 a, 405 b a pneumatically driven pin 603 a, 603 b, respectively, contacts the base portion 601 a, 601 b of the moveable grippers 405 a, 405 b, pushing the base portion 601 a, 601 b forward (toward the frontwall 103 a of the SRD housing), and thus causing the finger portion 409 a, 409 b to move backward as shown in FIG. 6A. The pneumatic actuator (not shown) for the pins 603 a, 603 b is housed within the plenum 107, and the pins 603 a, 603 b slide through openings (not shown) in the backside 103 b of the SRD housing in order to contact the base portion 601 a, 601 b of the moveable grippers 405 a, 405 b. A pair of springs 605 a, 605 b bias the moveable grippers 405 a, 405 b in a closed position (FIG. 6B) absent the pins 603 a, 603 b contact with the base portion 601 a, 601 b of the moveable grippers 405 a, 405 b, respectively.

[0030]FIGS. 7A and 7B are a side and a front cross sectional view, respectively, showing an optional drying mechanism employed within the inventive SRD of FIG. 1. As shown in FIGS. 7A and 7B, the optional drying mechanism comprises a Teflon tube 701 which extends preferably along the vertical diameter of the substrate 201. A first end of the Teflon tube 701 is coupled to a source 702 of semiconductor grade clean dry inert gas (e.g., nitrogen, CO2, AR, HE etc.), and a second end of the Teflon tube 701 has a cap 703, or is otherwise sealed, to prevent gas flow therethrough. The Teflon tube 701 is mounted in close proximity to the front surface of the substrate 201. A plurality of holes 705 exist in the face of the Teflon tube 701 which faces the substrate 201. The Teflon tube 701 or any similar drying mechanism is preferably configured to be unobtrusive in size so as not to block the majority of the substrate 201's surface from contact with the flow of air being pulled in through the vents 105 a-f and being drawn across the surface of the substrate 201 via the plenum 107, and so as not to block the movement of the main shield 213 (e.g., the Teflon tube 701 is mounted to the frontwall). The number and the spacing between the plurality of holes 705, the flow rate of inert gas, and the spacing between the Teflon tube 701 and the substrate 201 is selected such that smooth low-flow laminar stream of inert gas assists in blowing and/or evaporating fluid from the surface of the substrate 201. Because fluid may be more difficult to remove from the edge of the substrate 210, the spacing between the holes 705 decreases in the area of the Teflon tube 701 which corresponds to the edge of the substrate 201. Although a thin tube shaped drying mechanism is preferred, other shapes may be employed (showerheads, square, rectangular, etc.). Similarly, the drying mechanism may be any size (e.g., equal in area to the substrate to be dried, etc.)

[0031] In operation, to rinse and dry a substrate 201, the slideable door 120 slides along the tracks 123 a, 123 b to an open position wherein the opening 118 is exposed, as shown in FIGS. 1A and 1B. The flywheel 205 is in a predetermined position wherein the proximity sensor 209 detects the metal flag 211 such that the base portions 601 a, 601 b of the moveable grippers 405 a, 405 b are aligned in front of the pins 603 a, 603 b. The pins 603 a, 603 b are driven forward and contact the moveable gripper's base portions 601 a, 601 b to open the moveable grippers 405 a, 405 b as shown in FIG. 6A, while the links 401 a, 401 b move forward carrying the main shield 213 forward such that it no longer surrounds the grippers 403 a-c, 405 a-b. A substrate handler (not shown) lowers the substrate 201 through the opening 111 and places the substrate 201 on the fixed grippers 403 a-c. The fixed grippers 403 a-c support the substrate 201 in a fixed position with the center of the substrate 201 below the center of the flywheel 205. A pneumatic actuator (not shown) gradually retracts the pins 603 a, 603 b such that the moveable grippers 405 a, 405 b gradually close, placing the tip regions 411 a, 411 b (FIGS. 4 and 5) in contact with the substrate 201, as the door 121 slides to a closed position.

[0032] Thereafter, the flywheel 205 begins to rotate. Because the substrate 201's center is offset from the center of the flywheel 205 in the direction of the fixed grippers 403 a-c, rotation forces the substrate 201 firmly in the direction of the fixed grippers 403 a-c. Accordingly, minimal force is experienced by the moveable grippers 405 a, 405 b and the substrate 201 is unlikely to become unseated from the grippers 403 a-c, 405 a-b.

[0033] The flywheel 205 initially rotates at a slow speed (e.g., 100 to 500 revolutions per minute (rpm)) while the rinsing fluid nozzles 208 a, 208 b supply rinsing fluid to the center of the front and back surfaces of the substrate 201. It has been found that 400 rpm provides optimal rinsing of a vertically oriented substrate, as additional energy is required to overcome the force of gravity. That is, at substrate rotation speeds of 400 rpm or more, rinsing fluid may travel upward from the substrate's center, to the upper edge of the substrate. After the substrate 201 is sufficiently rinsed (e.g., approximately 12 sec.), the rinsing fluid nozzles 208 a, 208 b shut off, the optional heat lamp 115 turns on, a flow of nitrogen is introduced to the surface of the substrate 201 via the tube 701, and the motor 207 increases the rotational speed of the flywheel 205 (e.g., to approximately 1000 to 2500 rpm) such that rinsing fluid is displaced from the substrate 201 via the increased rotational speed, and/or dried from the substrate 201 via the heat lamp 115 and/or the nitrogen flow.

[0034] During both the rinsing and drying steps, rinsing fluid is flung from the substrate 201 to the substrate facing surfaces of the shield system. The majority of the fluid is received by the main shield 213, however, fluid may also land on the lower shield 215, the higher shield 217, the lower unshielded portions of the housing, or may condense on the top 103 c of the SRD housing 103.

[0035] In its preferred embodiment, the main shield 213 is angled such that fluid which impacts the main shield 213 is at least partially reflected therefrom toward the front side 103 a of the SRD housing and therefore does not collect on the main shield 213 forming droplets which may fall on the substrate 201 positioned therebelow. Further, the shields 213, 215 and 217 are preferably hydrophilic, so that fluid which is not reflected therefrom travels therealong in a sheet, rather than forming droplets which may fall onto the substrate 201.

[0036] Fluid flows from the substrate facing surface of the higher shield 217 to the top/non-substrate-facing surface of the main shield 213. Fluid travels from the non-substrate-facing surface of the main shield 213 to the non-substrate-facing surface of the lower shield 215, and from the non-substrate-facing surface of the lower shield 215 to the backside 103 b of the SRD housing 103. The rinsing fluid flows along the backside 103 b of the SRD housing 103 to the bottom of the SRD housing 103 f where fluid is removed by the pump (not shown).

[0037] Similarly, fluid flows from the substrate-facing surface of the main shield 213 to the non-substrate-facing surface of the lower shield 215. Due to the preferred steep angle of the lower shield 215, any fluid that lands on either the substrate facing surface or the non-substrate-facing surface of the lower shield 215 flows quickly to the backside 103 b of the SRD housing. Any fluid which reaches the top 103 c of the SRD housing will tend to flow therealong (due to the slope of the housing's top) to the housing's second sidewall 103 e. Preferably the housing's top 103 c is also hydrophilic. However, if fluid droplets form on the top 103 c of the SRD housing they will fall onto the non-substrate-facing surfaces of the shield system and travel therealong, rather than contacting the substrate 201.

[0038] As the substrate 201 rotates, fluid flows along the surface of the substrate 201, rinsing residue therefrom. Some of the fluid enters the end effectors 407 of the plurality of grippers. However, within the end effectors 407, fluid flows along the smooth, radial and preferably hydrophilic surfaces of the tip region 411 a, 411 b, and therefore is easily displaced therefrom by rotational force as the flywheel and the substrate 201 rotate. Any fluid which reaches the point where the tip regions 411 a, 411 b join, may also flow therefrom via the hole 413. Accordingly, the entire surface of the substrate 201 is dried, even those regions in contact with the plurality of grippers 403 a-c, 405 a-b.

[0039] To further aid in drying of the substrate 201, and to encourage the flow of fluid along the shield system toward the backside 103 b of the SRD housing 103, the plenum 107 is maintained at a lower pressure (e.g., 2 inches of water) than the environment within and surrounding the SRD 101 (e.g., approximately atmospheric pressure). Accordingly, a laminar air flow is drawn in through the vents 105 a-d across the surface of the substrate 201 and into the plenum 107 via openings in the backside 103 b of the SRD housing. This air flow aids in substrate drying, and due to the close vertical spacing of the shields 213, 215 and 217, tends to blow fluid along the surfaces thereof, toward the backside 103 b of the SRD housing 103.

[0040] After the substrate 201 is sufficiently dry (e.g., after the heat lamp 115 and the nitrogen flow have been on for approximately 5 to 20 seconds), the motor 207 slows the rotation of the flywheel 205 to approximately 5 rpm so that the proximity sensor 209 positioned on the backside 103 b of the SRD housing can detect the flag 211 when the flag 211 is in front of the proximity sensor 209. When the flag 211 is detected by the proximity sensor 209, the proximity sensor 209 signals the motor 207 to stop. Accordingly, the flywheel 205 stops rotating when the flywheel 205 and the substrate 201 are in a known position. Specifically, the substrate 201 is in the position it was in when placed in the SRD 101. The substrate 201 ideally is oriented prior to entry to the SRD 101.

[0041] In this known position, the base portion 601 a, 601 b of the moveable grippers 405 a, 405 b are positioned in front of the pins 603 a, 603 b and the pneumatic actuator (not shown) drives the pins 603 a, 603 b forward to contact the base portions 601 a, 601 b of the moveable grippers 405 a, 405 b and thus to open the moveable grippers 405 a, 405 b. The door 113 slides open and a substrate handler (not shown) extracts the rinsed and dried substrate 201.

[0042] The foregoing description discloses only the preferred embodiments of the invention, modifications of the above disclosed apparatus and method which fall within the scope of the invention will be readily apparent to those of ordinary skill in the art. For instance, the shield system may comprise one or any number of shields which may be hydrophilic, designed to reflect fluid, to direct airflow to the substrate, and/or closely spaced vertically to encourage fluid flow therealong (in the presence of laminar air flow). The shield system may be angled so as to direct fluid to the frontside, or to the first or second sidewalls of the SRD housing. The shield's substrate facing and non-substrate facing surfaces need not be parallel. Additionally, the shield system is described as having cone shaped shields which slant from a larger diameter to a smaller diameter. This configuration achieves desired fluid flow along the top of the shield system, and also directs air flow toward the main surface of the substrate to aid in drying thereof. It will be understood that the upper portion of the shield may assume other vertically and/or horizontally staggered configurations so as to achieve the desired fluid flow. Likewise, if airflow to the substrate is desired, it may be achieved with other shield or side wall configurations. Further benefits may be achieved by providing ribs (extending in the direction of, e.g. perpendicularly to, the sidewalls) along the non substrate facing surface of the shield. Finally, although the inventive shield system is preferably used for single substrate drying, aspects of the invention are equally advantageous for multiple substrate batches. The specific flag/sensor employed for substrate orientation may vary. The inert gas drying mechanism, and the mechanism for inducing pressure variations to facilitate drying may vary, as may the number of grippers and the specific configuration of grippers. The inventive principal of biasing the moveable grippers in a normally closed position, and of separating the opening actuators from the rotating grippers may be achieved via a number of configurations and yet remain within the scope of the present invention. In fact, any number of inventive aspects of the inventive SRD can be employed alone or in combination; the shield or shields, the inert gas drying mechanism, the grippers, the end effectors, the eccentric positioning, the preferred RPM rinse, the substrate orienter, etc. In fact, many of these inventive aspects are applicable to substrate spinners generally, and need not be limited to use on the SRD disclosed (e.g., the eccentric positioning, the gripper design, the substrate orienter) or may be employed within either a spin-rinser or a spin-drier. Thus, as used herein spinners include spin-rinsers and SRD's and spin-rinsers include apparatuses which spin and rinse, and which may or may not include drying (SRD's). Naturally, aside from the inventive fluid flow aspects, (e.g., the preferred RPM rinse, and the shield design for fluid flow) the remaining inventions are applicable to spinners, spin rinsers or SRD's of any orientation (horizontal, etc.). The shields are equally applicable for directing air flow regardless of substrate orientation (e.g., horizontal, vertical, etc.).

[0043] Accordingly, while the present invention has been disclosed in connection with the preferred embodiments thereof, it should be understood that other embodiments may fall within the spirit and scope of the invention, as defined by the following claims. 

The invention claimed is:
 1. A method of spinning, rinsing and drying a substrate comprising: rotating a vertically oriented substrate; spraying fluid on the rotating substrate; and at least partially reflecting fluid away from the substrate when the fluid is displaced from the substrate to a surface above the substrate.
 2. The method of claim 1 further comprising at least partially sheeting fluid along a hydrophilic surface above the substrate to a position which is not above the substrate.
 3. The method of claim 1 further comprising transferring fluid from a substrate facing surface of a first shield above the substrate, to a non-substrate-facing surface of a second shield.
 4. The method of claim 3 further comprising directing air toward the substrate via the first and second shield.
 5. A method of spinning, rinsing and drying a substrate comprising: rotating a vertically oriented substrate; spraying fluid on the rotating substrate; and at least partially sheeting fluid along a hydrophilic surface above the substrate to a position which is not above the substrate.
 6. The method of claim 5 further comprising transferring fluid from a substrate facing surface of a it first shield positioned above the substrate, to a non-substrate facing surface of a second shield.
 7. The method of claim 6 further comprising directing air toward the substrate via the first and second shield.
 8. A method of spinning, rinsing and drying a substrate comprising: rotating a vertically oriented substrate; spraying fluid on the rotating substrate; and directing air toward the substrate via a shield.
 9. The method of claim 8 wherein directing air toward the substrate via a shield comprises directing air toward the substrate via a plurality of shields.
 10. The method of claim 8 wherein directing air toward the substrate comprises directing air toward the substrate via a plurality of shields.
 11. A method of spinning, rinsing and drying a substrate comprising: rotating a vertically oriented substrate; spraying fluid on the rotating substrate; and transferring fluid away from a region above the substrate via a plurality of shields.
 12. The method of claim 11 further comprising directing air toward the substrate via the plurality of shields.
 13. The method of claim 11 further comprising: sheeting fluid along one or more hydrophilic surfaces of the plurality of shields.
 14. The method of claim 11 further comprising at least partially reflecting fluid away from the substrate when the fluid is displaced from the substrate to a surface above the substrate.
 15. The method of claim 11 further comprising moving at least one of the plurality of shields in a horizontal direction from a position above the substrate to a position not above the substrate and thereafter unloading the vertically oriented substrate from a substrate support.
 16. A method of spin rinsing a vertically oriented substrate, comprising: supporting a substrate in a vertical orientation; spraying fluid on the substrate; and rotating the substrate at a speed which is high enough to cause the fluid to travel upward from the center of the substrate, to the upper edge of the substrate.
 17. The method of claim 16 wherein the substrate is rotated at a speed of 400 rpm or more.
 18. The method of claim 16 wherein the substrate is rotated at a speed of 400 rpm. 